Heretofore, verifying whether the operation result or working result of a dispenser corresponds to the instruction of the user or not is performed by eye, using graduations or the like attached to a pipette tip or the like, or at most only by measurement of the air pressure in a pipette tip by a pressure sensor installed in the dispenser to detect lack of suction, liquid level and tip blockage.
Furthermore, in the case where a process is carried out by automated equipment that performs a series of operations sequentially and automatically, after the series of operations finishes, the verification has been done by no more than measuring the final liquid amount or the like obtained, and the operation has not been verified at each step during the process nor automatically.